isl_printer_print_{basic_,}{set,map}: don't start new line in omega format

For the isl format, the new line was removed in 9a54ed5
(isl_printer_print_basic_{set,map}: don't start new line in isl format,
Sun Feb 13 09:05:48 2011 +0100).

Additionally, remove the parameter declaration.
Printing out the parameter declaration for each (basic) set or map
is not very convenient. Instead, we now support printing the parameter
declaration through isl_printer_print_space.